The purpose of this continuing study is to monitor the hospital environment and protective isolation rooms for sources of microorganisms which can, given the opportunity, colonize and eventually infect the host-impaired cancer patient. As such sources are detected, procedures are instituted to prevent recurrence. Examples of problem areas detected last year are: 1) Certain contaminated foods, 2) contaminated ice from hospital kitchen, 3) contaminated Coca cola, 4) improperly cleaned ICU rooms and 5) contaminated denture cups.